Several diameric idole alkaloids from Vinca rosea (flowering periwinkle) including vinblastine, vincristine, leurosine, leurosidine, leurosivine, and rovidine are powerful cancer chemotherapeutic agents. Vinblastine and vincristine have been particularly used for about ten years in the treatment of Hodgkin's disease and chilhood leukemia, respectively. Because of the exceedingly low isolated yield of these compounds from the plant, it is important to develop laboratory syntheses of these anti-tumor agents if more extensive clinical use and testing are to be achieved. Total syntheses from common chemicals also provide structural modifications which may not be available from the natural alkaloid and which are essential for structure-activity studies. Our present work is directed towards the synthesis of the monomeric indole alkaloids vobasine, sarpagine, and vincadifformine, each of which represents one-half of different dimeric indole alkaloids. This work involves developing new synthetic techniques to apply to the construction of the alkaloid molecules. We are particularly interested in preparing simple derivatives of the natural alkaloids to see if anti-tumor activity can be preserved in modified structures that are more accessible by laboratory synthesis than the plant alkaloids themselves. A major goal in our research is to find derivatives which lack the side effects associated with the plant alkaloids but which retain their anti- tumor activity.